/*
 * This module is a place to implement commands and functions for
 * sector write-protection (locking and unlocking, checking current
 * lock state) on AMD-style flash chips.
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include "flash.h"

extern struct flash_bank_info flash_bank_info[2];

/*
 * Some common functions for Spansion PL-N flash: common between
 * flash lock-state retrieval and active PPB programming.
 */

static
pln_special_mode_entry(base_addr, mode_opc)
	uint32_t base_addr;
	uint16_t mode_opc;
{
	if (do_w16(base_addr + 0xAAA, 0xAA)) {
bad_w16:	fprintf(stderr,
"unexpected response to w16 in PL-N special mode entry sequence - aborting\n");
		return(-1);
	}
	if (do_w16(base_addr + 0x554, 0x55))
		goto bad_w16;
	if (do_w16(base_addr + 0xAAA, mode_opc))
		goto bad_w16;
	return(0);
}

static
pln_special_mode_exit(base_addr)
	uint32_t base_addr;
{
	if (do_w16(base_addr, 0x90)) {
bad_w16:	fprintf(stderr,
"unexpected response to w16 in PL-N special mode exit sequence - aborting\n");
		return(-1);
	}
	if (do_w16(base_addr, 0x00))
		goto bad_w16;
	return(0);
}

/*
 * flash lock-state implementation with its helper functions.
 */

static
issue_read_id(base_addr)
	uint32_t base_addr;
{
	if (do_w16(base_addr + 0xAAA, 0xAA)) {
bad_w16:	fprintf(stderr,
	"unexpected response to w16 in read ID cmd sequence - aborting\n");
		return(-1);
	}
	if (do_w16(base_addr + 0x554, 0x55))
		goto bad_w16;
	if (do_w16(base_addr + 0xAAA, 0x90))
		goto bad_w16;
	return(0);
}

static
issue_reset_cmd(base_addr)
	uint32_t base_addr;
{
	if (do_w16(base_addr + 0xAAA, 0xF0)) {
		fprintf(stderr,
	"unexpected response to w16 when resetting flash to read mode!\n");
		return(-1);
	}
	return(0);
}

static
read_mode_lock_word(base_addr, word_offset, retp)
	uint32_t base_addr, word_offset;
	uint16_t *retp;
{
	if (do_w16(base_addr + 0xAAA, 0xAA)) {
bad_w16:	fprintf(stderr,
	"unexpected response to w16 in mode lock query sequence - aborting\n");
		return(-1);
	}
	if (do_w16(base_addr + 0x554, 0x55))
		goto bad_w16;
	if (do_w16(base_addr + 0xAAA, 0x60))
		goto bad_w16;
	if (do_w16(base_addr + word_offset, 0x48))
		goto bad_w16;
	if (do_r16(base_addr + word_offset, retp) < 0)
		return(-1);
	return(0);
}

flashcmd_lock_state(argc, argv, bank)
	char **argv;
{
	struct flash_bank_info *bi;
	struct amd_lock_info *li;
	struct lock_group_desc *grp;
	uint32_t offset, part_addr;
	uint16_t word;
	unsigned ng, nb;

	if (argc > 2) {
		fprintf(stderr, "error: too many arguments\n");
		return(-1);
	}
	if (flash_detect(bank, 0) < 0)
		return(-1);
	bi = flash_bank_info + bank;
	li = bi->amd_lock;
	if (!li) {
		fprintf(stderr,
			"Operation not supported for this flash chip type\n");
		return(-1);
	}
	offset = 0;
	for (ng = 0; ng < li->ngroups; ng++) {
		grp = li->groups + ng;
		if (grp->part_begin) {
			part_addr = bi->base_addr + offset;
			if (issue_read_id(part_addr) < 0)
				return(-1);
		}
		if (offset == 0 && li->have_status_word_3) {
			if (do_r16(bi->base_addr + 6, &word) < 0)
				return(-1);
			printf("Global status word 3: %04X\n", word);
		}
		if (offset == 0 && li->have_status_word_7) {
			if (do_r16(bi->base_addr + 0xE, &word) < 0)
				return(-1);
			printf("Global status word 7: %04X\n", word);
		}
		for (nb = 0; nb < grp->nblocks; nb++) {
			if (do_r16(bi->base_addr + offset + 4, &word) < 0)
				return(-1);
			printf("Sector%s at 0x%X: %s\n",
				grp->is_group ? " group" : "", offset,
				(word & 1) ? "locked" : "unlocked");
			offset += grp->block_size;
		}
		if (grp->part_end) {
			if (issue_reset_cmd(part_addr) < 0)
				return(-1);
		}
	}
	if (li->have_mode_lock_bits) {
		if (read_mode_lock_word(bi->base_addr, 0x14, &word) < 0)
			return(-1);
		printf("Password Protection Mode lock: %04X\n", word);
		if (issue_reset_cmd(bi->base_addr) < 0)
			return(-1);
		if (read_mode_lock_word(bi->base_addr, 0x24, &word) < 0)
			return(-1);
		printf("Persistent Protection Mode lock: %04X\n", word);
		if (issue_reset_cmd(bi->base_addr) < 0)
			return(-1);
	}
	if (li->have_pln_lock_reg) {
		if (pln_special_mode_entry(bi->base_addr, 0x40) < 0)
			return(-1);
		if (do_r16(bi->base_addr, &word) < 0)
			return(-1);
		printf("PL-N Lock Register: %04X\n", word);
		if (pln_special_mode_exit(bi->base_addr) < 0)
			return(-1);
	}
	return(0);
}

/*
 * Here comes a version of the above lock-state checking code,
 * modified for use from within ppb-program-all and ppb-erase-all
 * functions for chips that don't do this work internally.
 */

static
int_lock_state_check(bi, sought_state)
	struct flash_bank_info *bi;
{
	struct amd_lock_info *li = bi->amd_lock;
	struct lock_group_desc *grp;
	uint32_t offset, part_addr;
	uint16_t word;
	unsigned ng, nb;
	int lock_state;

	offset = 0;
	for (ng = 0; ng < li->ngroups; ng++) {
		grp = li->groups + ng;
		if (grp->part_begin) {
			part_addr = bi->base_addr + offset;
			if (issue_read_id(part_addr) < 0)
				return(-1);
		}
		for (nb = 0; nb < grp->nblocks; nb++) {
			if (do_r16(bi->base_addr + offset + 4, &word) < 0)
				return(-1);
			lock_state = word & 1;
			if (lock_state != sought_state)
				break;
			offset += grp->block_size;
		}
		if (lock_state != sought_state) {
			if (issue_reset_cmd(part_addr) < 0)
				return(-1);
			return(0);
		}
		if (grp->part_end) {
			if (issue_reset_cmd(part_addr) < 0)
				return(-1);
		}
	}
	return(1);
}

/*
 * Spansion PL-J PPB write functions, referenced from lock_info structures
 * in fldevs.c device descriptions.
 */

static
plj_ppb_write_op(base_addr, is_erase, retp)
	uint32_t base_addr;
	uint16_t *retp;
{
	if (do_w16(base_addr + 0xAAA, 0xAA)) {
bad_w16:	fprintf(stderr,
	"unexpected response to w16 in PPB command sequence - aborting\n");
		return(-1);
	}
	if (do_w16(base_addr + 0x554, 0x55))
		goto bad_w16;
	if (do_w16(base_addr + 0xAAA, 0x60))
		goto bad_w16;
	if (do_w16(base_addr + 4, is_erase ? 0x60 : 0x68))
		goto bad_w16;
	usleep(1200);			/* per S29PL-J datasheet */
	if (do_w16(base_addr + 4, is_erase ? 0x40 : 0x48))
		goto bad_w16;
	if (do_r16(base_addr + 4, retp) < 0)
		return(-1);
	return(0);
}

plj_ppb_program_one(bi, sector_addr)
	struct flash_bank_info *bi;
	uint32_t sector_addr;
{
	uint16_t stat;
	unsigned pulsecnt;
	int rc;

	for (pulsecnt = 0; pulsecnt < 25; ) {
		rc = plj_ppb_write_op(bi->base_addr + sector_addr, 0, &stat);
		if (rc < 0)
			return(rc);
		pulsecnt++;
		if (!(stat & 1))
			continue;
		printf("PPB 0x%X programmed with %u pulse%s\n", sector_addr,
			pulsecnt, pulsecnt > 1 ? "s" : "");
		return amd_reset_cmd(bi);
	}
	fprintf(stderr, "PPB 0x%X programming FAILED, tried %u pulses\n",
		sector_addr, pulsecnt);
	return(-1);
}

plj_ppb_program_all(bi)
	struct flash_bank_info *bi;
{
	struct amd_lock_info *li = bi->amd_lock;
	struct lock_group_desc *grp;
	uint32_t offset;
	unsigned ng, nb;
	int rc;

	offset = 0;
	for (ng = 0; ng < li->ngroups; ng++) {
		grp = li->groups + ng;
		for (nb = 0; nb < grp->nblocks; nb++) {
			rc = plj_ppb_program_one(bi, offset);
			if (rc < 0)
				return(rc);
			offset += grp->block_size;
		}
	}
	printf("Verifying PPB programming\n");
	rc = int_lock_state_check(bi, 1);
	if (rc < 0)
		return(rc);
	if (rc)
		return(0);
	fprintf(stderr, "flash error: one or more PPBs failed to program\n");
	return(-1);
}

static
plj_ppb_erase_cycle(bi)
	struct flash_bank_info *bi;
{
	uint16_t stat;
	unsigned pulsecnt;
	int rc;

	printf("Performing PPB erase cycle\n");
	for (pulsecnt = 0; pulsecnt < 1000; ) {
		rc = plj_ppb_write_op(bi->base_addr, 1, &stat);
		if (rc < 0)
			return(rc);
		pulsecnt++;
		if (stat & 1)
			continue;
		printf("PPB erase cycle succeeded after %u pulse%s\n",
			pulsecnt, pulsecnt > 1 ? "s" : "");
		return amd_reset_cmd(bi);
	}
	fprintf(stderr, "PPB erase cycle FAILED, tried %u pulses\n", pulsecnt);
	return(-1);
}

plj_ppb_erase_all_single(bank, raw_mode)
{
	struct flash_bank_info *bi = flash_bank_info + bank;
	unsigned pulsecnt;
	uint16_t stat;
	int rc;

	if (raw_mode)
		return plj_ppb_erase_cycle(bi);
	printf("Programming all PPBs before erase cycle\n");
	rc = plj_ppb_program_all(bi);
	if (rc < 0)
		return(-1);
	printf("Entering PPB erase and verify loop\n");
	for (pulsecnt = 0; ; ) {
		if (pulsecnt >= 1000) {
			fprintf(stderr,
		"flash error: unable to complete PPB erase after %u pulses\n",
				pulsecnt);
			return(-1);
		}
		rc = plj_ppb_write_op(bi->base_addr, 1, &stat);
		if (rc < 0)
			return(rc);
		pulsecnt++;
		if (stat & 1)
			continue;
		putchar('.');
		fflush(stdout);
		rc = amd_reset_cmd(bi);
		if (rc < 0)
			return(rc);
		rc = int_lock_state_check(bi, 0);
		if (rc < 0)
			return(rc);
		if (rc)
			break;
	}
	printf("\nPPB erase complete, total pulses: %u\n", pulsecnt);
	return(0);
}

plj_ppb_erase_all_dualbank(reqbank, raw_mode)
{
	int altbank = !reqbank;
	unsigned pulsecnt;
	uint16_t stat;
	int rc;

	if (flash_detect(altbank, 0) < 0)
		return(-1);
	if (flash_bank_info[0].device != flash_bank_info[1].device) {
		fprintf(stderr, "error: mismatch between two flash banks\n");
		return(-1);
	}
	if (raw_mode)
		return plj_ppb_erase_cycle(flash_bank_info + reqbank);
	printf("Programming all PPBs in flash bank 0\n");
	rc = plj_ppb_program_all(&flash_bank_info[0]);
	if (rc < 0)
		return(-1);
	printf("Programming all PPBs in flash bank 1\n");
	rc = plj_ppb_program_all(&flash_bank_info[1]);
	if (rc < 0)
		return(-1);
	printf("Entering PPB erase and verify loop\n");
	for (pulsecnt = 0; ; ) {
		if (pulsecnt >= 1000) {
			fprintf(stderr,
		"flash error: unable to complete PPB erase after %u pulses\n",
				pulsecnt);
			return(-1);
		}
		rc = plj_ppb_write_op(flash_bank_info[0].base_addr, 1, &stat);
		if (rc < 0)
			return(rc);
		pulsecnt++;
		if (stat & 1)
			continue;
		putchar('.');
		fflush(stdout);
		rc = amd_reset_cmd(&flash_bank_info[0]);
		if (rc < 0)
			return(rc);
		rc = int_lock_state_check(&flash_bank_info[0], 0);
		if (rc < 0)
			return(rc);
		if (!rc)
			continue;
		rc = int_lock_state_check(&flash_bank_info[1], 0);
		if (rc < 0)
			return(rc);
		if (rc)
			break;
	}
	printf("\nPPB erase complete, total pulses: %u\n", pulsecnt);
	return(0);
}

/*
 * Front end functions for PPB operation commands.
 */

flashcmd_ppb_program(argc, argv, bank)
	char **argv;
{
	struct flash_bank_info *bi;
	struct amd_lock_info *li;
	u_long offset_arg;
	struct sector_info *sp;
	char *strtoul_endp;

	if (argc != 3) {
inv:		fprintf(stderr, "usage: %s %s sector-offset\n",
			argv[0], argv[1]);
		return(-1);
	}
	offset_arg = strtoul(argv[2], &strtoul_endp, 16);
	if (*strtoul_endp)
		goto inv;
	if (flash_detect(bank, 0) < 0)
		return(-1);
	bi = flash_bank_info + bank;
	li = bi->amd_lock;
	if (!li || !li->ppb_program_one) {
		fprintf(stderr,
			"Operation not supported for this flash chip type\n");
		return(-1);
	}
	if (offset_arg >= bi->geom->total_size) {
		fprintf(stderr,
		"error: specified offset exceeds flash bank size (0x%lx)\n",
			(u_long) bi->geom->total_size);
		return(-1);
	}
	if (get_flash_sector_table(bi) < 0)
		return(-1);
	for (sp = bi->sectors; sp->size; sp++)
		if (sp->start == offset_arg)
			break;
	if (!sp->size) {
		fprintf(stderr,
	"error: specified offset not aligned to a flash sector boundary\n");
		return(-1);
	}
	return li->ppb_program_one(bi, sp->start);
}

flashcmd_ppb_program_all(argc, argv, bank)
	char **argv;
{
	struct flash_bank_info *bi;
	struct amd_lock_info *li;

	if (argc > 2) {
		fprintf(stderr, "error: too many arguments\n");
		return(-1);
	}
	if (flash_detect(bank, 0) < 0)
		return(-1);
	bi = flash_bank_info + bank;
	li = bi->amd_lock;
	if (!li || !li->ppb_program_all) {
		fprintf(stderr,
			"Operation not supported for this flash chip type\n");
		return(-1);
	}
	return li->ppb_program_all(bi);
}

flashcmd_ppb_erase_all(argc, argv, bank)
	char **argv;
{
	struct flash_bank_info *bi;
	struct amd_lock_info *li;
	int raw_mode;

	switch (argc) {
	case 2:
		raw_mode = 0;
		break;
	case 3:
		if (!strcmp(argv[2], "raw")) {
			raw_mode = 1;
			break;
		}
		/* FALL THRU */
	default:
		fprintf(stderr, "usage: %s %s [raw]\n", argv[0], argv[1]);
		return(-1);
	}
	if (flash_detect(bank, 0) < 0)
		return(-1);
	bi = flash_bank_info + bank;
	li = bi->amd_lock;
	if (!li || !li->ppb_erase_all) {
		fprintf(stderr,
			"Operation not supported for this flash chip type\n");
		return(-1);
	}
	return li->ppb_erase_all(bank, raw_mode);
}